Sealed self-contained fluidic cooling device

ABSTRACT

A cooling system and method for cooling electronic components, including IC dies. The cooling system employs a cooling device that includes a composite structure having first and second plates arranged substantially in parallel and bonded together to define a sealed cavity therebetween. The first plate has a surface that defines an outer surface of the composite structure and is adapted for thermal contact with at least one electronic component. A mesh of interwoven strands is disposed within the cavity and lies in a plane substantially parallel to the first and second plates, with the strands bonded to the first and second plates. A fluid is contained and sealed within the cavity of the composite structure, and flows through interstices defined by and between the strands of the mesh.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis made are identified in the Application Data Sheet filed with thepresent application and are incorporated by reference under 37 CFR 1.57and made a part of this specification.

BACKGROUND

1. Field of the Invention

The present invention generally relates to cooling systems forelectronic components. More particularly, this invention relates to asealed cooling device that contains a fluid and a mesh material throughwhich the fluid flows to promote heat transfer through the device.

2. Description of the Related Art

Cooling of electronic devices has become increasingly challenging aselectronics have evolved. As manufacturing processes are constantlyrefined, the migration to smaller design processes and the incumbentreduction in operating voltage has not kept pace with the increasedcomplexity of faster integrated circuits (ICs). Increasing number oftransistors in combination with increasing operating frequencies hasresulted in higher numbers of switching events over time per device. Asa result, within the same market space and price range, ICs are becomingmore and more sophisticated and power-hungry with every generation.

Compared to earlier generations, the implementation of smaller designprocesses has allowed the integration of more electronic building blockssuch as transistors and capacitors on the same footprint. Consequently,area power densities have increased, resulting in smaller diesdissipating higher thermal load. As a result, formerly sufficient,passive heat spreaders and coolers often do not provide adequatecooling. While sophisticated fin designs and powerful fans increase theactive surface area useable for offloading thermal energy to theenvironment, even extremely well designed coolers are hitting inherentlimitations. In particular, significant limitations stem from thebottleneck of limited heat conductivity of the materials used, andspecifically the fact that passive heat transfer throughout a solidstructure is limited by the thermal conductance coefficient of thematerial and the cross sectional area of the structure.

In a two-dimensional heat spreader of uniform thickness, the amount ofheat energy decreases as a square function of the distance from thesource, where the thermal conductance coefficient of the material andthe cross sectional area define the slope of the decrease. Therefore,even the most highly conductive material will not be able to maintain aneven temperature distribution across the entire surface of the coolingdevice. Any gradient, on the other hand, will cause a decrease incooling efficiency since the temperature difference (.DELTA.T) betweenthe cooler's surface and the environment is the primary limiting factorfor thermal dissipation to the surrounding.

In view of the above, it is desired that coolers transfer heat from aheat source as quickly and efficiently as possible to provide a uniformtemperature distribution or isothermicity at the cooler's surface. Incombustion engines, liquid cooling has become the method of choice,using the fact that a liquid (e.g., water) is taking up thermal energyand subsequently being pumped to a remote radiator where it releases theabsorbed heat. In electronic devices, liquid cooling is still onlymarginally accepted for reasons that include the inherent risk ofspills, cost overhead, and complexity of the installation, whichinvolves routing of tubing and installation of radiators. Alternatively,some self-contained liquid cooling devices have been proposed andmarketed.

The four primary factors defining the efficacy of a liquid coolingdevice are the uptake of heat by the cooling fluid at the heat source,the transport rate of the fluid away from the heat source, theoffloading of heat to the solid components of the cooler, and finallythe dissipation rate of heat into the environment. The exchange of heatbetween the fluid and the cooling device largely depends on the routingof the flow of the coolant within the device. If the channels are toowide, laminar flow can cause a decrease in efficacy of heat exchangebetween the fluid and the device. Therefore, it is desirable to have acapillary system to achieve an optimal surface to volume ratio. Suchcapillary systems have been referred to as microchannel systems.

Different technologies have been employed to create microchannels,including etching and crosshatching of small grooves into a coolingdevice and even into the die of an electronic device to be cooled, suchtechnologies have required relatively elaborate steps in their designand manufacturing process. Commonly-assigned U.S. Pat. No. 7,219,715 toPopovich, the contents of which are incorporated herein by reference,describes an alternative approach using a mesh or woven screen that isbetween and bonded to two foils that define a flow cavity. A genericrepresentation of this type of approach is depicted by a cooling device10 shown in FIG. 1, in which a pair of foils 12 and 14 are bondedtogether, and a mesh 16 is contained within a cavity 18 defined by andbetween the foils 12 and 14. The interstices between the warp and weftstrands 20 of the mesh 16, as well as the gaps between the strands 20and the bordering foils 12 and 14, allow the passage of a cooling fluid,providing direct contact with the fluid for heat absorption and transferheat through the bonding contacts with the foils 12 and 14. As furtherrepresented in FIG. 2, Popovich also provides an opening 22 in one ofthe foils 14 that provides for direct contact of the cooling fluidwithin the device 10 with the die 24 of an IC device, which isrepresented in FIG. 2 as projecting into the cavity 18 through theopening 22. FIGS. 3 through 4 represent variations of the cooling device10 of FIG. 1. In FIG. 3, the device 10 is modified to include coolingfins 28 that promote heat dissipation to the surrounding environment. InFIG. 4, the device 10 is modified to include an integrated pump 30 forforcing the flow of the cooling fluid within the device 10. As would beexpected, the fins 28 of FIG. 3 and the pump 30 of FIG. 4 can also becombined in the same cooling device 10.

An advantage of the cooling devices represented in FIGS. 1 through 4 isattributable to the tortuous course of the microchannels through themesh 16, meaning that in addition to an X-Y labyrinth of interstices, aZ-plane of tortuousness is created that further increases the internalsurface area for heat exchange between the fluid and the solidcomponents of the cooling device 10.

Though the approach represented in FIGS. 1 through 4 is thermallyefficient, exposure of the IC die 24 to the cooling fluid requires asealing feature 32 (such as an adhesive seal, O-ring, etc.) around theopening 22 in the cavity 18 to allow direct fluid passage over the die24. Aside from any potential reliability problems, the requirement for asealing feature 32 can complicate the serviceability of the coolingdevice 10, and may render the device 10 ill-suited for aftermarketretrofitting by certain end users with limited technical skills.

In addition to Popovich, the use of microchannels for coolant fluids hasbeen known for some time, as evidenced by U.S. Pat. No. 4,450,472 toTuckerman et al. The preferred embodiment featured in this patentintegrated microchannels into the die of the microchip to be cooled andcoolant chambers. U.S. Pat. No. 5,801,442 also describes a similarapproach. Still other approaches have focused on the combined use ofcoolant phase change (condensation) and microchannels, an example ofwhich is U.S. Pat. No. 6,812,563. U.S. Pat. No. 6,934,154 describes asimilar two-phase approach including an enhanced interface between an ICdie and a heatspreader based on a flip-chip design and the use of athermal interface material. U.S. Pat. Nos. 6,991,024, 6,942,018, and6,785,134 describe electroosmotic pump mechanisms and vertical channelsfor increased heat transfer efficiencies. Variations of microchanneldesigns include vertical stacking of different orientational channelblocks as described in U.S. Pat. No. 6,675,875, flexible microchanneldesigns using patterned polyimide sheets as described in U.S. Pat. No.6,904,966, and integrated heating/cooling pads for thermal regulation asdescribed in U.S. Pat. No. 6,692,700.

Additional efforts have been directed to the manufacturing ofmicrochannels. U.S. Pat. Nos. 7,000,684, 6,793,831, 6,672,502, and6,989,134 are representative examples, and disclose formingmicrochannels by sawing, stamping, crosscutting, laser drilling, softlithography, injection molding, electrodeposition, microetching,photoablation chemical micromachining, electrochemical micromachining,through-mask electrochemical micromachining, plasma etching, water jet,abrasive water jet, electrodischarge machining (EDM), pressing, folding,twisting, stretching, shrinking, deforming, and combinations thereof.All of these methods, however, share the drawback of requiring a more orless elaborate and expensive manufacturing process.

SUMMARY OF THE INVENTION

The present invention is a cooling system and method for coolingelectronic components, including IC dies. The cooling system employs acooling device that includes a composite structure comprising first andsecond plates arranged substantially in parallel and bonded together todefine a sealed cavity therebetween. At least one of the first andsecond plates has a surface that defines an outer surface of thecomposite structure and is adapted for thermal contact with at least oneelectronic component. At least one and preferably multiple separatemeshes, each of interwoven strands, are disposed within the cavity andlie in a plane substantially parallel to the first and second plates,with their strands bonded to the first and second plates. A fluid iscontained and sealed within the cavity of the composite structure, andflows through interstices defined by and between the strands of themeshes.

The cooling method entails absorbing heat dissipated by an electroniccomponent with a first plate arranged substantially in parallel andbonded to a second plate so as to define a composite structure and asealed cavity between the first and second plates. The first plate has asurface that defines an outer surface of the composite structure and isadapted for thermal contact with the electronic component. The absorbedheat is transferred through the cavity and into the second plate via afluid and at least one mesh contained in the cavity. The mesh lies in aplane substantially parallel to the first and second plates, andcomprises interwoven strands that are bonded to the first and secondplates and define interstices through which the fluid is able to flow.The fluid acts as a secondary heat absorbent and a thermal transportmedia that transports thermal energy to the mesh at a distance from thefirst plate. After traveling through the cavity, the absorbed heat isdissipated to the environment with the second plate.

In a preferred embodiment, the cooling device has a plate-mesh-platelaminate construction, in which portions of the plates, preferablyincluding their edges, are raised so that by laminating the platestogether a channel system is defined between the plates. At least one ofthe plates is preferably configured to define first order channels ormacrochannels within the cooling device in order to direct the generalflow of a cooling fluid through the channel system between the plates.Fluid movement through the channel system can be augmented by a pump.

Within the channel system, a tortuous three-dimensional labyrinth ofmicrochannels is established by interstices between strands of the oneor more meshes. The meshes are preferably bonded to each of the platesat substantially every bump of each strand resulting from the strandspassing over and under transverse strands of each mesh. Difficultiesassociated with directly contacting an electronic component with acooling fluid are overcome by hermetically sealing the cooling device toprevent contact between the cooling fluid and an electronic componentcooled by the cooling device, and then thermally contacting theelectronic device with one of the plates or a heat-slug formed as partof the plate or as a separate component attached to the plate.

According to a preferred aspect of the invention, the hermetical sealestablishes a self-contained, spill-proof, and leak-proof cooling systemthat can easily be adapted to fit any heat source, while maintaining theadvantages of a sealed system. The potential drawback of reducedefficacy of heat uptake compared to a fully immersed IC die can beconsidered relatively minor compared to the limitations posed by theoverall rate of thermal dissipation to the environment that can resultin a thermal saturation of the entire cooling apparatus. Additionaladvantages of the invention include rapid heat distribution throughoutthe entire cooling device, uncomplicated installation and maintenance,cost-effectiveness, and good scalability that allows for large-scalecooling devices.

Other objects and advantages of this invention will be betterappreciated from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 represents an open cooling device for fluid immersion of anelectronic device in accordance with the prior art.

FIG. 2 shows the cooling device of FIG. 1 mounted and sealed with anelectronic device to be cooled.

FIGS. 3 and 4 show prior art cooling devices mounted and sealed withelectronic devices in a manner similar to that shown in FIG. 2, butfurther equipped with, respectively, cooling fins to provide increasedsurface area for promoting heat dissipation and an integrated pump forfluid displacement.

FIG. 5 represents a first embodiment of a cooling device of the presentinvention, in which the device defines a completely sealed enclosurebetween a pair of bonded plates, and has a mesh material within theenclosure and bonded to the plates.

FIG. 6 shows the device of FIG. 5 mounted to an electronic device to becooled.

FIG. 7 shows a cooling device equipped with cooling fins that provideincreased surface area for promoting heat dissipation in accordance witha second embodiment of the invention.

FIG. 8 shows the cooling device of FIG. 7 mounted to an electronicdevice in a manner similar to that shown in FIG. 6.

FIG. 9 shows a cooling device with an integrated pump for fluiddisplacement in accordance with a third embodiment of the invention.

FIG. 10 shows the cooling device of FIG. 9 mounted to an electronicdevice in a manner similar to that shown in FIG. 6.

FIG. 11 shows a cooling device that includes an integrated pump as shownin FIG. 9 and cooling fins as shown in FIG. 7 in accordance with afourth embodiment of the invention.

FIG. 12 shows the cooling device of FIG. 11 mounted to an electronicdevice in a manner similar to that shown in FIG. 6.

FIG. 13 shows a top view of a cooling device equipped with a pump, andembossed regions that define partitions within the cooling device todirect fluid flow in macrochannels within the device in accordance witha fifth embodiment of the invention.

FIG. 14 is a cross-sectional view of FIG. 13 along section line A-A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides a self-contained, closed-loop fluidcooling device suitable for cooling a wide variety of electroniccomponents, including those with high power densities such asmicroprocessors and power conversion devices used in computers. FIG. 5represents a cooling device 110 of this invention comprising anisothermal plate 111 having a composite construction, in which arelatively pliant mesh 116 is sandwiched between two foils or plates 112and 114 that are substantially parallel to each other. The mesh 116 isrepresented as being composed of individual strands 120 that are woventogether, generally transverse to each other and conventionally referredto as warp and weft strands 120. The mesh 116 and plates 112 and 114 arepreferably formed of materials having physically and chemicallycompatible properties, including materials having the same composition,though various material combinations are possible. For example,individual strands 120 of the mesh 116 can be formed by an individualwire, braided wires, bundled wires, etc., of copper, silver, aluminum,carbon, or alloys thereof, and the plates 112 and 114 can be formed ofthe same or similar materials. As discussed below, heat transfer occursby conduction through the plates 112 and 114 and mesh 116, such thatpreferred materials for these components are thermally conductive,though the use of other materials including polymeric and nonmetallicmaterials is also foreseeable. Suitable thicknesses for the plates 112and 114 and mesh 116, suitable cross-sectional shapes and dimensions forthe mesh strands 120, and suitable weaves (including strands per inch)for the mesh 116 may depend on the particular application and thematerials from which these components are formed.

As evident from FIG. 5, the peripheral edges 134 of both plates 112 and114 are preferably raised relative to the remainder of the plates 112and 114, such as by embossing, to form a relief in each plate 112 and114 that promotes the rigidity of the plates 112 and 114 and furtherdefines a continuous peripheral surface at which the plates 112 and 114can be bonded to each other, such as with a solder alloy, braze alloy,adhesive, etc. With the plates 112 and 114 laminated together, thereliefs define a cavity 118 between the plates 112 and 114. As will bediscussed in reference to FIGS. 13 and 14, additional embossing can beperformed on one or both plates 112 and 114 to define within the cavity118 a channel system between the plates 112 and 114, by which particularflow routes can be established within the device 110. Three-dimensionalstructures formed by such additional embossing have the furtheradvantage of increasing the mechanical stability of the cooling device110.

As evident from FIG. 5, the mesh 116 within the cavity 118 of thecomposite plate 111 may have approximately the same thickness as theheight of the cavity 118 (as measured in the direction normal to theplane of the plate 111). The peaks 136 projecting from both sides of themesh 116 are preferably bonded, such as by soldering or brazing, to theplates 112 and 114 to establish a highly-conductive thermal contactbetween the mesh 116 and both plates 112 and 114. Bonding also serves tocross-link the plates 112 and 114, which resists any shearing forces towhich the plates 112 and 114 are subjected and contributes additionalmechanical stability and rigidity to the plate 111. The warp and weftstrands 120 of the mesh 116 form interstices that are more or lessfreely penetrable by any fluid, yet define tortuous paths that avoidlaminar flow conditions within the cavity 118 that would reduce the heattransfer rate between the cooling fluid, the plates 112 and 114, and themesh 116. Assuming the plate 114 is in thermal contact with a heatsource, e.g., an electronic component 124 shown in FIG. 6, heat transferfrom the component 124 is through the plate 114, through the cavity 118containing the mesh 116 and fluid, and then through the plate 114, fromwhose outer surface heat is dissipated by convection. More particularly,heat transfer through the cooling device 110 is by thermal conductionthrough the plate 114, the mesh 116, and then the plate 112, and byconvention between the plate 114 and the cooling fluid and between thecooling fluid and the plate 112, as well as convection through thecooling fluid from the plate 114 to the mesh 116 and convection throughthe cooling fluid from the mesh 116 to the plate 112. Accordingly, heattransfer is generally in a single direction through the thickness of thecomposite plate 111, and the fluid acts as a secondary heat absorbentand a thermal transport media capable of transporting thermal energy tothe mesh 116 at a distance from the plate 114.

As generally known in the art, suitable coolant fluids include liquidssuch as water, mineral spirits/oils, alcohols, and fluorocarbonatederivatives, though various other fluids could also be used, includingair, vapor, etc., depending on the required temperature range ofoperation. For example, in extremely cold environments, a fluid withlower viscosity is a better choice than in extremely hot environments.Various other parameters for choosing a cooling fluid exist and are wellknown, and therefore will not be discussed in any further detail here.

As evident from FIG. 5, the composite plate 111 lacks an opening inwhich the cooling fluid within the cooling device 110 is able todirectly contact an electronic component intended to be cooled with thedevice 110. Instead, the device 110 is self-contained with the coolingfluid being hermetically sealed within the cavity 118, such that coolingof an electronic component 124 (FIG. 6) is achieved by thermallycontacting the component 124 with one of the plates 112/114. Thisapproach greatly simplifies the installation and maintenance of thedevice 110.

Thermal contact between the component 124 and plate 114 is shown in FIG.6 as being promoted with the use of a heat-slug 138, which is preferablyformed of a high thermally-conductive material that also has highthermal capacitance, a notable but nonlimiting example of which iscopper and its alloys. The heat slug 138 can be defined by a portion ofthe plate 114, or can be separately formed and then attached to theplate 114. While a small loss in heat transfer is associated with theinterfaces 140 and 142 between the heat slug 138 and the plate 114 andcomponent 124, the resistance to heat transfer caused by theseinterfaces 140 and 142 is relatively minor compared to the resistanceencountered when dissipating heat from the cooling device 110 to theenvironment (typically atmospheric air) surrounding the device 110.Moreover, the heat slug 138 is preferably able to offer sufficientthermal capacitance to buffer transient temperature spikes of thecomponent 124. The thermal capacitance of the slug 138 also overcomesother problems, such as the potential for localized boiling of thecooling fluid in proximity to hot-spots of the component 124, theoccurrence of which could greatly reduce the cooling efficacy of thedevice 110.

Because the cooling fluid assists the plates 112 and 114 in conductingheat from the component 124, the coefficient of thermal conductance ofthe material(s) used to form the plates 112 and 114 is less importantthan in structures that rely on passive heat transfer. As such, a widervariety of materials could be used to form the composite plate 111 andits individual components. Moreover, because the plate 111 is hollow,the total amount of material used is substantially lower than in acomparable solid structure, resulting in reduced material costs formanufacturing the cooling device 110. A related issue is the mechanicalstability of the cooling device 110. Hollow structures generally exhibitonly a minor reduction in rigidity as compared to a solid body of thesame dimensions. The rigidity of the device 10 is promoted as a resultof the peripheral edges 134 of the plates 112 and 114 being bondedtogether, as well as bonding of the mesh 116 to both plates 112 and 114.Consequently, the cooling device 110 can be much lighter but yet nearlyas strong and rigid as a solid heat spreader of comparable size.

As evident from FIG. 7, the cooling device 110 may include fins 128 topromote heat transfer to the surrounding environment. While fins 128 areshown on only the upper plate 112, the lower plate 114 or both plates112 and 114 could be so equipped. As known in the art, the fins 128effectively increase the surface area of the cooling device 110 and,thus, facilitate offloading of the heat to the surrounding environment.

The cooling device 110 may further include a pump 130 as shown in FIG. 9by which the cooling fluid is recirculated through the cavity 118,generally in a direction or directions parallel to the mesh 116. A widevariety of pumps are possible and suitable for use in the device 110,and the choice of which will be primarily dependent on the specificapplication since pressure and noise requirements need to be taken intoconsideration. Notable but nonlimiting examples of suitable pump typesinclude centrifugal, positive displacement, rotary, and osmotic pumpsthat are commercially available and have been used in prior coolingsystems for electronic components. As seen in FIG. 11, the coolingdevice 110 may also include a combination of fins 128 and pump 130.

FIGS. 9 and 11 depict another aspect of the invention, in which meshsegments 116A and 116B are employed in place of the single unitary mesh116 of FIGS. 5 through 8. The mesh segment 116A is a primary meshjuxtaposed and preferably directly aligned and over the electroniccomponent 124 for heat uptake, and one or more mesh segments 116Blocated near the periphery of the device 110 and preferably surround themesh segment 116A for faster offloading of heat. Heat transfer betweenthe mesh segments 116A and 116B is generally via the cooling fluid andvia the plates 112 and 114.

FIGS. 8, 10, and 12 represent, respectively, the use of the devices 110shown in FIGS. 7, 9, and 11 for dissipating heat from an electroniccomponent 124. In each of FIGS. 8 and 12, a fan 148 is also shown forpromoting heat transfer from the fins 128 through forced convection.Otherwise, the device 110 may rely on natural convection to dissipateheat.

Notably, with the inclusion of the pump 130, heat transfer through thecooling fluid is enhanced as a result of the fluid flow becomingturbulent as a result of the fluid being forced to flow through theinterstices between the strands 120 of the mesh 116. More particularly,assuming the plate 114 is in thermal contact with the electroniccomponent 124 as shown in FIGS. 6, 8, 10, and 12, heat transfer throughthe cooling device 110 is by thermal conduction through the plate 114,the mesh 116, and then the plate 112, and by turbulent forced conventionbetween the plate 114 and the cooling fluid and between the coolingfluid and the plate 112, as well as turbulent forced convection throughthe cooling fluid from the plate 114 to the mesh 116 and turbulentforced convection through the cooling fluid from the mesh 116 to theplate 112. Even so, because the cooling fluid is recirculated throughthe cooling device 110, heat transfer is through the device 110 isgenerally through the thickness of the composite plate 111, in otherwords, from the electronic component 124, through the plate 114, throughthe cavity 118 containing the mesh 116 and fluid, and then through theplate 112, from whose outer surface heat is dissipated by convection.

FIGS. 13 and 14 depict a variation of the cooling device 110 of FIGS. 5through 12, modified to include embossed regions 144 within the interiorof the cavity 118. The embossed regions 144 are represented as formingwalls or dividers within the cavity 118 to define a system of channels146 in fluidic series. As shown in FIG. 13, the channels 146 define acircuitous route (identified by arrows) for the cooling fluid throughthe cooling device 110, with flow through the device 110 beingmaintained at a desired rate with a pump 130. Alternatively, flow mayoccur opposite the direction indicated in FIG. 13. Another alternativeis to use the channel 146 immediately downstream from the pump 130 as amacrochannel or manifold to direct the flow of the cooling fluid inseries through the remaining channels 146, or simultaneously in parallelthrough two or more of the channels 146. The mesh 116 can be a singleunit having portions clamped between the embossed regions 144 and theopposing interior surface regions of the plate 114, or can be made up ofmesh segments that are each sized to individually fit within one of thechannels 146.

While the invention has been described in terms of specific embodiments,it is apparent that other forms could be adopted by one skilled in theart. For example, the functions of the components of the cooling device110 could be performed by components of different construction butcapable of a similar (though not necessarily equivalent) function, thecooling device 110 and its components could differ in appearance andconstruction from the embodiments shown in the Figures, and appropriatematerials could be substituted for those noted. Therefore, the scope ofthe invention is to be limited only by the following claims.

What is claimed is:
 1. A cooling device comprising: a first plate and asecond plate bonded together to define a sealed cavity between the firstplate and the second plate, the first plate having an outer surfaceadapted for thermal contact with an electronic component; a first meshdisposed within the sealed cavity and lying in a plane substantiallyparallel to the first and second plates, the first mesh comprisinginterwoven strands extending between the first plate and the secondplate; a fluid contained and sealed within the sealed cavity; andinterstices defined by and between the interwoven strands of the meshthrough which the fluid within the sealed cavity is able to flow.
 2. Thecooling device of claim 1, further comprising a heat slug disposed onthe outer surface of the first plate and of sufficient size to buffertransient heat spikes of the electronic component.
 3. The cooling deviceof claim 2, wherein the outer surface of the cooling device is limitedto thermal contact with the electronic component through the heat slug.4. The cooling device of claim 3, wherein the heat slug physicallycontacts the electronic component.
 5. The cooling device of claim 1,further comprising a second mesh disposed within the sealed cavity andlying in the plane substantially parallel to the first and secondplates, the second mesh spaced apart from the first mesh and comprisinginterwoven strands extending between the first plate and the secondplate.
 6. The cooling device of claim 5, wherein the first mesh ispositioned within the sealed cavity to align with a heat slug disposedon the outer surface of the first plate, and wherein the second mesh ispositioned at a periphery of the first mesh.
 7. The cooling device ofclaim 5, wherein the interwoven strands of the first mesh are bonded tothe first plate and the second plate, and the interwoven strands of thesecond mesh are bonded to the first plate and the second plate
 8. Thecooling device of claim 5, further comprising a pump mounted within thesealed cavity, the pump configured to circulate the fluid within thesealed cavity in a flow direction generally parallel to the first andsecond plates so that fluid flow becomes turbulent as the fluid isforced to flow through the interstices.
 9. The cooling device of claim5, wherein the sealed cavity is configured to convect heat from thefirst mesh and/or the first plate to the second mesh via the fluid. 10.The cooling device of claim 1, wherein the sealed cavity is configuredso that heat transfer from the electronic component is through the firstplate, through the sealed cavity containing the first mesh and thefluid, and through the second plate, from which heat is dissipated byconvection to the environment.
 11. A method of transferring thermalenergy from an electronic component, the method comprising: absorbingheat dissipated by an electronic component with a first plate arrangedsubstantially in parallel and bonded to a second plate so as to define asealed cavity between the first and second plates, the first platehaving a surface that defines an outer surface of the sealed cavity andadapted for thermal contact with the electronic component, a fluidcontained within the sealed cavity; conducting heat from the first plateand through the sealed cavity and into the second plate via a first meshcontained in the sealed cavity, the first mesh lying in a planesubstantially parallel to the first and second plates, the first meshcomprising interwoven strands extending between the first and secondplates and defining interstices through which the fluid is able to flow;convecting heat from the first plate and/or the first mesh to the secondplate via the fluid contained within the sealed cavity; and dissipatingthe absorbed heat from the second plate.
 12. The method of claim 11,further comprising providing a pump mounted within the sealed cavity.13. The method of claim 12, further comprising forcing fluid through theinterstices so that the fluid flow through the interstices becomesturbulent.
 14. The method of claim 11, further comprising providing asecond mesh, the second mesh spaced from the first mesh, the second meshlying in the plane substantially parallel to the first and secondplates, the second mesh comprising interwoven strands extending betweenthe first and second plates and defining interstices through which thefluid is able to flow.
 15. The method of claim 14, further comprisingconvecting heat from the first plate and/or the first mesh to the secondmesh via the fluid contained within the sealed cavity.
 16. The method ofclaim 11, wherein the sealed cavity is configured so that heat transferfrom the electronic component is primarily through the first plate,through the sealed cavity containing the mesh and the fluid, and throughthe second plate, from which the heat is dissipated by convection to theenvironment.
 17. A method of manufacturing a cooling device comprising:positioning a mesh between a first plate having an outer surface adaptedfor thermal contact with an electronic component and a second plate, themesh comprising interwoven strands; and bonding the first plate and thesecond plate together along bonding edges so as to define a sealedcavity between the first and second plates, wherein the mesh and a fluidis contained and sealed within the sealed cavity.
 18. The method ofclaim 17, further comprising bonding the interwoven strands of the meshto the first plate and the second plate.
 19. The method of claim 17,further comprising positioning a second mesh between the first andsecond plates, the second mesh comprising interwoven strands and spacedapart from the mesh.
 20. The method of claim 17, further comprisingaligning the mesh with a heat slug disposed on the outer surface of thefirst plate.